What do understand by the efficiency of a machine? By using a block and tackel a man can raise a load of 720 N by an effort of 180 N. Find the mechanical advantage of the method.

Which of the following is not a characteristic of s waves? a. travel slower than p waves. b. cannot be detected in locations more than 105° from an earthquake’s epicenter. c. travel through solids and liquids. d. only affect coastal regions.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Determine the fraction of the magnitude of kinetic energy lost by a neutron (m1 = 1.01 u) when it collides head-on and elastically with a target particle at rest which is 21h (heavy hydrogen, m = 2.01 u).